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Licensed Unlicensed Requires Authentication Published by De Gruyter June 1, 2005

First report on a potato I family chymotrypsin inhibitor from the seeds of a Cucurbitaceous plant, Momordica cochinchinensis

  • A. Y. K. Tsoi , R. C. H. Wong , T.-B. Ng and W.-P. Fong
From the journal Biological Chemistry


A 7514-Da chymotrypsin inhibitor was isolated from the seed extract of Momordica cochinchinensis (Family Cucurbitaceae) by chromatography on chymotrypsin Sepharose 4B and subsequently by C18 reversed-phase HPLC. This inhibitor, named MCoCI, possessed remarkable thermostability and was stable from pH 2 to 12. MCoCI also inhibited subtilisin, but had at least 50-fold lower inhibitory activity towards trypsin and elastase. Amino acid sequencing of a peptide fragment of MCoCI revealed a sequence of 23 amino acids. Comparison of this sequence and the molecular mass with those of other protease inhibitors suggests that MCoCI belongs to the potato I inhibitor family.

Published Online: 2005-06-01
Published in Print: 2004-02-05

Copyright © 2004 by Walter de Gruyter GmbH & Co. KG

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